Because it uses infrared technology, Spitzer has several advantages that allow astronomers to peer into hidden regions of the Universe.
Vast, dense clouds of gas and dust, or interstellar dust, fills much of space, blocking our view of visible light. Infrared light, however, can penetrate these clouds, allowing us to see deeper into the universe.
Infrared light also allows us to see cooler objects across the Universe. Some of these objects are too dim to be seen in visible light, but can be seen using the infrared.